The Physicochemical, Antioxidant, and Color Properties of Thin Films Based on Chitosan Modified by Different Phenolic Acids
Round 1
Reviewer 1 Report
The author made some changes to the manuscript. I t can be accepted to publish in the jurnal.
Author Response
On behalf of my co-authors and myself, I want to express our thanks for the valuable comments and constructive recommendations, which were very helpful for revising and improving our paper. Thank you for your comment, accepting the previous corrections.
Reviewer 2 Report
Coatings-1528861 (Article)
The physicochemical, antioxidant and color properties of thin films based on chitosan modified by different phenolic acids
Her in this manuscript, authors have compared various phenolic acids (ferulic acid, caffeic acid, tannic acid, gallic acid) in consideration as chitosan cross-linkers. The physicochemical properties of obtained materials in thin film form were studied, such as thermal and mechanical properties, surface free energy and water vapor permeation rate measurement, antioxidant activity, as well as film color.
- Finally confirmed that phenolic acids are effective cross-linkers of chitosan-based materials. They improved mechanical and thermal properties as well as provided antioxidant activity of films.
- English is ok but can be improved
- Figures are adequate, Fig 1 clarity is missing
- Tables are sufficient with ample information.
- Literature review must be redone, with more similar works for evaluation
- R&D can be increased with more comparison
- Conclusions must be elaborated
- Instruments Model numbers, software versions are missing
Accept after major revision.
With Regards,
Comments for author File: 
Comments.docx
Author Response
On behalf of my co-authors and myself, I want to express our thanks for the valuable comments and constructive recommendations, which were very helpful for revising and improving our paper. We have studied the comments carefully before the revision of our article. All changes in the revised manuscript have been marked with the "Track Changes" function in Microsoft Word. We hope that the revised version of the manuscript will be acceptable for publication.
Comment 1: English is ok but can be improved
The manuscript have been corrected by native speaker.
Comment 2: Figures are adequate, Fig 1 clarity is missing
The quality and clarity of Figure 1 have been improved. The abbreviations from the graphs were expanded in the figure description.
Comment 3: Tables are sufficient with ample information.
Thank you very much for the comment
Comment 4: Literature review must be redone, with more similar works for evaluation
Thank you very much for the comment. It is now corrected.
Comment 5: R&D can be increased with more comparison
We improved R&D part.
Comment 6: Conclusions must be elaborated
It is now corrected. We hope it is acceptable now.
Comment 7: Instruments Model numbers, software versions are missing
The details about equipment and software have been completed.
Reviewer 3 Report
The subject of the paper “The physicochemical, antioxidant and color properties of thin films based on chitosan modified by different phenolic acids” by Kaczmarek-Szczepańska et al. is interesting in general, however the following points need to be addressed:
- The abstract part is showing a general description of the work, it should represents a part of the most important results in the case of results, and also give us more details on the percentages of phenolic acids, etc. please consider these points and rewrite it.
- The introduction part needs a bit more details about biopolymers and their importance, hence I recommend the following review papers to foster this part:
- Bahrami, R., et al. (2020). Modification and improvement of biodegradable packaging films by cold plasma; a critical review. Critical Reviews in Food Science and Nutrition, 1-15.
- Garavand, F., et al. (2020). A comprehensive review on the nanocomposites loaded with chitosan nanoparticles for food packaging. Critical reviews in food science and nutrition, 1-34.
- Hadidi, M., et al. (2022). Plant protein-based food packaging films; recent advances in fabrication, characterization, and applications. Trends in Food Science & Technology, 120, 154-173.
- The first part of 2. Materials and Methods… should have a title like chemicals ….
- Lines 60-61: Phenolic acid solutions at 1% concentration were heated to completely dissolve compounds… in all experimental parts, please report all details of the experiments, in this part for instance, the heating temperature, the way of mixing or agitation (heater stirrer or ultrasonic?), the instrument details (brand, company, etc.), the heating time, and etc. are all missed, please modify this part and other parts accordingly.
- 1. Sample preparation could be changed to film preparation, then please note the film preparation procedure (solvent casting, extrusion, or whatever) and then report the reference that you used to do so, do the same thing for other parts.
- Use the proper reference for 2.2. Mechanical testing section and other experiments.
- Use the same format for the equations.
- In line 114: use the proper subscripts for equation components.
- The statistical analysis part is missed, please insert the way you did it in detail.
- In all tables and figures with the results, signify the significant differences between groups with letter.
- In Table 4, the line numbers are mixed with the table contents!
- In discussion part, please compare your results with the proper references in this field to see how your crosslinkg approach affects the chitosan film properties.
- In conclusion part, a future trend regarding the use of biopolymers and the modification approaches could strengthen the text.
Author Response
On behalf of my co-authors and myself, I want to express our thanks for the valuable comments and constructive recommendations, which were very helpful for revising and improving our paper. We have studied the comments carefully before the revision of our article. All changes in the revised manuscript have been marked with the "Track Changes" function in Microsoft Word. We hope that the revised version of the manuscript will be acceptable for publication.
Comment 1: The abstract part is showing a general description of the work, it should represents a part of the most important results in the case of results, and also give us more details on the percentages of phenolic acids, etc. please consider these points and rewrite it.
Thank you for the suggestion. It is now corrected.
Comment 2: The introduction part needs a bit more details about biopolymers and their importance, hence I recommend the following review papers to foster this part:
- Bahrami, R., et al. (2020). Modification and improvement of biodegradable packaging films by cold plasma; a critical review. Critical Reviews in Food Science and Nutrition, 1-15.
- Garavand, F., et al. (2020). A comprehensive review on the nanocomposites loaded with chitosan nanoparticles for food packaging. Critical reviews in food science and nutrition, 1-34.
- Hadidi, M., et al. (2022). Plant protein-based food packaging films; recent advances in fabrication, characterization, and applications. Trends in Food Science & Technology, 120, 154-173.
Thank you very much for your proposition. These are very valuable items and we used them in the Introduction part.
Comment 3: The first part of 2. Materials and Methods… should have a title like chemicals ….
Yes of course. We used Chemicals as title of first part of Materials and Methods section.
Comment 4: Lines 60-61: Phenolic acid solutions at 1% concentration were heated to completely dissolve compounds… in all experimental parts, please report all details of the experiments, in this part for instance, the heating temperature, the way of mixing or agitation (heater stirrer or ultrasonic?), the instrument details (brand, company, etc.), the heating time, and etc. are all missed, please modify this part and other parts accordingly.
All missing information have been completed (details about materials preparation and equipment information).
Comment 5: Sample preparation could be changed to film preparation, then please note the film preparation procedure (solvent casting, extrusion, or whatever) and then report the reference that you used to do so, do the same thing for other parts.
We changed the name of this part. It is: “Fabrication of chitosan/phenolic acid films”. The films were prepared by solvent evaporation method in room conditions (temperature and humidity). We completed the reference and the references of next parts of Materials and Method section.
Comment 6: Use the proper reference for 2.2. Mechanical testing section and other experiments.
The reference have been completed.
Comment 7: Use the same format for the equations.
We made appropriate corrections. All equations are in the same format.
Comment 8: In line 114: use the proper subscripts for equation components.
All subscripts for equation components have been completed.
Comment 9: The statistical analysis part is missed, please insert the way you did it in detail.
The statistical part was added as “2.9. Statistics” part.
Comment 10: In all tables and figures with the results, signify the significant differences between groups with letter.
Thank you very much for the comment. It is now corrected. We signed the significant differences of obtained results with pure chitosan as it was our control.
Comment 11: In Table 4, the line numbers are mixed with the table contents!
It have been corrected.
Comment 12: In discussion part, please compare your results with the proper references in this field to see how your crosslinkg approach affects the chitosan film properties.
Thank you for the comment. We improved the discussion part.
Comment 13: In conclusion part, a future trend regarding the use of biopolymers and the modification approaches could strengthen the text.
Thank you for the valuable comment. It is now corrected.
Round 2
Reviewer 2 Report
The paper has been improved well
but need to redraw figure 1 and 2 to become more clear in large size in X and Y axes, draw in black instead of gray color
Best regards
Author Response
Dear Reviewer, thank you for the comment. It is now corrected.
Reviewer 3 Report
The current version addressed all comments and acceptable in this format.
Author Response
Dear Reviewer, thank you very much.
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
Comments
Chitsan-phenolic acid composite films were prepared, and the physicochemical properties were evaluated in this work. This manuscript should not be published in the current state.
Research lacks novelty. The structural reason (the structural differences of phenolic acids) resulted in the different physicochemical properties of the chitsan-phenolic acid composite films should be supplemented.
Reviewer 2 Report
The manuscript authored by B. Kaczmarek-Szczepańska et al discussed the functions of films deriving from mixing chitosan and phenolics. It is an interesting but also well-studied topic.
My major concern is about the novelty of the present work. I believe much publication about chitosan/phenolics films has been reported, since even 5 yrs ago. Besides the physical, chemical, morphological, functional properties, the potential application and the comparison between chitosan/phenolic (simple mixing) and chitosan-phenolic (covalent conjugating) films were also reported.
Here are some other minors-
The term "cross-linker" is misleading. It makes readers think phenolics covalently cross-linked the chitosan chains.
Error bars were missed in some figs and tabs. Statistics was missed in the presented results.
RSA% of chitosan could not be 0.
Reviewer 3 Report
The authors presented the work on the physicochemical, antioxidant and color properties of thin films based on chitosan modified by different phenolic acids. The article topic is appropriate for this journal, however, the overall manuscript presentation starting with the introduction should be drastically improved, thus I recommend major revision.
The title should include also antioxidant and color properties.
Abstract should contain more info about the properties (including some measured values).
More keywords should be added.
The Introduction part is very poorly prepared; it is missing description of works by others (literature review) as well the broader picture about the problems and topic is prepared in a hard to comprehend manner or it’s even not relevant to the topic of the article.
Authors should extend the introduction part and should provide a clear connection between the awareness of the problem the state of the art available solution and focus more on the comparison of the similar technologies.
Material and Methods
The equations used should be numbered and placed in the text.
What was the concentration of the phenolic acid solution?
Results.
Figure 1 should be mentioned in the text before. Please add text before placing Figure 1 in section 3.1.
Adding the thickness of the thin films should be added to the results part and discussed.
Moreover dealing with the crosslinking of the FTIR results can be used to further confirm your claims.
Figure 2 has no real impact since the values for WVPR are shown in Table 1. Rather replace with the Figure showing pictures of the obtained thin films.
As in addition to Table 4 the picture of the films can be added. Was the coloration homogeneous across the whole film?
Section 3.5.
The first sentence should move to the discussion.
The color quality crucial as it may influence the appearance of edible films which affect the acceptance of foods to consumers.
Mentioning of the edible film can be avoided since there are not been described before or in the introduction. It just brings confusion.
In the discussion part please specify what is meant as dressing material. Since it is usually used as a biomedical term and not connected with food or edible film, which was implied in the manuscript. More literature cases should be added to discuss the results.
Reviewer 4 Report
The manuscript is presenting an interesting study. But needs some improvements.
Sometimes the authors used calcium chloride and sometimes CaCl2, please uniform in the text.
Please perform statistical analysis for Tables 1-4, and compared for example with CTS (as standard).
In the discussion section must be in details discussed about the results compared to existing literature regarding chitosan, crosslinking and tannins. Therefore, the section needs to be improved.
Reviewer 5 Report
After analyzing the Manuscript ID: coatings-1432685 "The physicochemical properties of thin films based on chitosan modified by different phenolic acids" I consider that it should be rejected for publication.
-The content of the manuscript is very poor, more experiments must be carried out.
–The difference should be explained with another publication of the working group. Some results are the same and this reference is not written in the manuscript.
Kaczmarek-Szczepa ´nska, B .; Wekwejt, M .; Mazur, O .; Zasada, L .; Pałubicka, A .; Olewnik-Kruszkowska, E. The Physicochemical and Antibacterial Properties of Chitosan-Based Materials Modified with Phenolic Acids Irradiated by UVC Light. Int. J. Mol. Sci. 2021, 22, 6472. https: // doi.org/10.3390/ijms22126472.
-It is recommended to carry out a better discussion of the results
-It is recommended to add new references on CS to increase the interest of the readers. CS is a very interesting biopolymer and should be reflected in the introduction.
Possible references.
Carbohydrate Polymers (2021), 273, 118616.
Brazilian Archives of Biology and Technology 53(3), 623-628, 2010.
Journal of Composites Science (2021), 5(6), 160.
Acta Hortic. 1296, 1153-1160. DOI: 10.17660/ActaHortic
Membranes (Basel, Switzerland) (2021), 11(6), 421.
-Compare the results obtained with others reported, for example in reference 19.
What is the difference between the products obtained and phenolic acid-g-CS
In general, the manuscript requires many modifications to be accepted.
